This invention relates to a forward-reverse shifting apparatus for a marine propulsion device of the water-jet type and more particularly to an improved reverse bucket arrangement for such a device.
The use of jet propulsion units in watercraft is very popular for a wide variety of reasons. With this type of unit, the watercraft is propelled in a forward direction by employing a jet nozzle from which water is expelled after being pressurized by an impeller. With this type of drive, it has been the practice to provide a reverse bucket or deflector that is swung into registry with the discharge nozzle and which redirects the discharge in a forward direction so as to achieve reverse drive of the watercraft. Such reverse buckets are normally swung into position from a retracted position below the nozzle or from a retracted position above the nozzle.
In accordance with these arrangements, it is also desirable to provide a position in which there will be no forward or reverse thrust or wherein the forward and reverse thrust balance each other to achieve a neutral operation. However, the prior art devices previously proposed have had certain disadvantages. For example, in the prior art type of arrangements, it has been necessary to hold the bucket in a partially opened, partially closed position during the neutral operation. As a result, the jet forces of the water issuing from the nozzle act on the bucket and tend to cause it to swing in one direction or the other. Therefore, it has been proposed to employ hydraulically actuated devices for operating the bucket. Obviously, this adds to the cost and complexity of the system.
Furthermore, certain of these devices have had to be held in a partial position to achieve the neutral operation. This requires a degree of accuracy in order to achieve the neutral condition and variations in the running of the engine, such as if the choke is activated, can cause speed differences which will result in the generation of either forward or reverse thrust since the neutral position varies with the amount of thrust being generated.
It is, therefore, a principal object of this invention to provide an improved reversing arrangement for a jet propulsion unit for a watercraft.
It is a further object of this invention to provide an improved reversing and neutral thrusting arrangement for a jet propulsion marine drive.
It is yet a further object of this invention to provide a simple yet highly effective arrangement for achieving both neutral and reverse operation with jet propulsion watercraft units.